1. Field of the Invention
The present invention relates generally to the field of fungal and odor control, and more specifically to providing a material that creates a uniform and continuous release of diphenyl vapor such that the emitted vapor effectively reduces malodors and the growth of fungi for an extended period of time.
2. Description of the Background
Diphenyl is an organic compound that has a variety of applications. Diphenyl's chemical structure is shown below:

Diphenyl is commonly manufactured in the form of a powder or flake. The powder/flake diphenyl is problematic to work with in that it is messy and is difficult to keep in one place. Thus, loose diphenyl granules or flakes are considered undesirable and may be considered a contaminant. However, diphenyl has a melting point of 70° C., permitting it to be melted to a liquid easily. The liquid is more easily handled than flake or powder diphenyl.
One application of diphenyl is in the prevention of mold and fungus growth. Diphenyl has been used as a preservative, particularly by impregnation of papers used in the transport of citrus fruits with diphenyl. Those papers could then be used to wrap the fruit, retarding mold and fungus growth. U.S. Pat. Nos. 2,173,453 and 2,746,872 (hereby incorporated by reference) disclose the preparation and use of such diphenyl-impregnated papers for this purpose. Currently, the primary uses for diphenyl are as a component in heat transfer fluids and in dyeing fabrics.
In addition to its anti-mold and anti-fungal properties, diphenyl also has a pleasant smell and odor counteractant properties and may also be used as a deodorizer. Indeed, there are many applications where both properties—a deodorizer and an anti-fungal/mold—may be desirable. Such instances may include putting diphenyl-containing products around areas of the home prone to water damage (e.g., basements, boats, closets, bathrooms) or for use in disaster area clean-up, particularly in areas affected by rain and/or flooding, to prevent both fungal growth as well as the odors associated with moisture/fungal growth. Diphenyl-containing materials may also be used as a deodorizing agent in hotels, bathrooms, kitchens, homes with pets, vehicles, and in smoking areas. Diphenyl is not readily water soluble, thus, may be useful as deodorizer or fungistat in drains or other areas where the product may come into regular contact with water.
Despite the wide ranging benefits of diphenyl, its use remains somewhat limited and primarily restricted to citrus fruit transportation. While diphenyl-impregnated paper is effective for wrapping fruit, delivery of diphenyl from paper is relatively rapid, thus exhausting the source of diphenyl quickly. That attribute renders such formulations ineffective in domains where longer delivery times of diphenyl are desired.
Two commercially available products using diphenyl for odor control are the Damp Check Magic Disk and Sun-Fresh Crystal Disk. The Crystal Disk is molded or cast, again, onto a paper substrate wherein the paper is a barrier to air movement. The product label states that the Crystal Disk is “often used in vacuum cleaners.” The paper substrate is fragile, flimsy, and lacks mechanisms of attachment suitable to fix the product at a particular location. Users are directed to place the device in return air locations, rather than supply airstream conduits.
There remains a need for a versatile and durable material that can serve as a vehicle for delivery of deodorizing, anti-fungal diphenyl. Here, we disclose a solid material impregnated with diphenyl that provides uniform and sustained release of diphenyl over an extended period of time. The solid material is easily impregnated with diphenyl, is structurally sound, can be manufactured into a variety of shapes and sizes, and is fire and heat resistant. The material has the capacity to release diphenyl over the course of 1-2 months, or longer, depending on the air flow and temperature of the environment in which it is placed.